Question

hich species in each pair is a better oxidizing agent under standard-state conditions? a. Br2 or Au3+ b. H2 or Ag+ c. Cd2+ or Cr3+ d. O2 in acidic media or O2 in basic media

Answer 1

Explanation:

It is known that species with higher value of reduction potential will act as a good oxidizing agent.

(a) Here we are given $Br_{2}$ and $Au^{3+}$. Reduction potential of $Br_{2}$ is 1.07 V and reduction potential of $Au^{3+}$ is 1.50 V.

As $Au^{3+}$ has higher value of reduction potential. Hence, $Au^{3+}$ acts as a better oxidizing agent than $Br_{2}$.

(b)  Here we are given $H_{2}$ and $Ag^{+}$. Reduction potential of $H_{2}$ is 0.00 V and reduction potential of $Ag^{+}$ is 0.80 V.

As $Ag^{+}$ has higher value of reduction potential. Hence, $Ag^{+}$ acts as a better oxidizing agent than $H_{2}$.

(c)  Here we are given $Cd^{2+}$ and $Cr^{3+}$. Reduction potential of $Cd^{2+}$ is -0.40 V and reduction potential of $Cr^{3+}$ is -0.74 V.

As  $Cd^{2+}$ has higher value of reduction potential than $Cr^{3+}$. Hence, $Cd^{2+}$ acts as a better oxidizing agent.

(d)  The given species are $O_{2}$ in acidic medium and $O_{2}$ in basic medium. Reduction potential of $O_{2}$ in acidic medium is 1.23 V and reduction potential of  $O_{2}$ in basic medium is 0.40 V.

Thus, we can conclude that $O_{2}$ in acidic medium is better oxidizing agent that $O_{2}$ in basic medium.